Boring machine



July 30, 1935. T. THoRsEN 2,009,822

BORING MACHINE Filed. Jan. 2o, 1932 2 sheets-sheet@ July 3o, 192.5.

T. THoRsEN BORING MACHINE Patented July 30, 1935 PATENT OFFICE I n BORING MACHINE Thor Thor'sen, Minneapolis, Minn., assigner to Storm Manufacturing Co.,` Inc., Minneapolis,

AMinn., a corporation of Minnesota Application January 20,

1 Claim.

My present invention relates to boring ina-` chines and more particularly to a boring machine for reestablishing, reboring and refinishing boresl in an engine cylinder block of accurate size and 5 alignment. The object of the invention is to provide a portable, self-contained, power-operated boring machine that is highlyeflicient and ofV compact formwhich permits the machine to be mounted on an engine cylinderV block without removing said block from the chassis of an automotive vehicle` and where it is necessary to work close to the cowl and other parts of the vehicle.

To the above end, generally stated, the inven-` tion consists of the novel devices and combinations of devices hereinafter describedand dened in the claim. i l

In the accompanying drawings, whichV illus? trate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a front elevation of the improved boring machine mounted on an engine cylinder block, some parts being broken away and sectioned; e

Fig. 2 is a View principally in section taken on the line 2-2 of Fig. l;

Fig. 3 is a fragmentary detail view with somev parts sectioned on the line 3--3 of Fig. 2;

Fig. 4 is a detail view partly in elevation and partly in section taken on the line 4 4 of Fig, 2; 30 Fig, 5 is a view partly inplan and partly in horizontal section taken on the line 5 5 of Fig- 4i J Fig. 6 is a detail view, on an enlarged scale, with some parts sectioned on the line 6-6 of Fig. 4; and

Figs. 'I and 8 are fragmentary detail views showing the micrometer.

The improved boring machine,as shown in` the drawings, is mounted on an engine cylinder block and indicated, as an entirety, by the numeral 9 with the exception of its cylinders I0.

The base II of the boring machine is designed to rest on the at top of the cylinder block 9 and support said machine perpendicular thereto. This base I I has a hollow raisedcentral portion which supports an upstanding .openended substantially cylindrical housing I2 that is 'integral therewith, This housing I2 has `at its yvertical center a gear compartment I3 having an open front normally closed by a displaceable cover plate I4. Circumferentially spaced sight openings I5 are formed in the raised central portion of the base II. Y Y A novel multiple cutter head I6 is detachably I5 secured by screw-threads, as indicated at I1, to

1932, Serial N0. 587,708

(Cl. T7-2) not shown, will be provided for retracting the cut- 10V ters I9 when the pilot 20 is retracted. VThe boring bar I8 is journaled at its lower end portion in upper and lower axially spaced and axially aligned bearings 22 in the housing I2 and located, the former above the. compartment I3 and 15 the latter below the same. These bearings 22 are rigidly and adjustably secured to the housing I2.

The pilot 2D extends axially through the cutter head I6 in axial alignment with Vthe boring bar I8 and projects above. said cutter head and is detachably secured by a coupling 23 to a long operatingrod 24 by which the pilot 2@ may be turned in the cutter head I6 to project or vretract the same. The operating rod 24 extends axially through the boring bar I8, is out of contact therewith and projects above the upper endv thereof. This operating rod 24 at its upper end portion extends through an axial hole inthe top of a micrometer thmble 25 which thimble affords a bearing therefor. VA depending tubular stem 2S integral withthe under side of the Vtop of the thimble 25 looselyusurrounds the operating rod 24 and extends axially into a' detachable top extension 21 of the boring bar i8, is connected thereto by screw-threads 2S for axial ad-` justment thereon, and is normally held from` turning with respect thereto by a set-screw 29. It may be here stated that the screw-threads 2 IY and 28 are of the Same number per inch.A

Normally the micrometer thimble 25 is locked to the operating rod`24 for rotation therewith by a wedge-acting pin 30 and a cooperating thumb-screw 3|. This rpin 3o is loosely mounted in an oblique bore in the top of the thimble and impingesl against the operating rod 24. The thumb-screw 3| extends into said bore, has screw-threaded engagement with the thimble 25 and impinges against the wedge pin 39 and holds the same in frictional contact with the operating rod 24 with sufficient pressure to cause the thimble 25 to rotate with said rod.

A hand-crank 32 detachably appliedto the upper end of the operating rod 24, Yand fragmentarily illustrated in Fig. 2 by means of Abroken lines,is provided for manuallyV turning'said rod to project or retract the pilot 2i' for adjusting the cutter I9.

Operating connections from an electric motor 33 are provided for simultaneously rotating the boring bar I8 and axially moving the same to impart like movements to the cutter head l. This electric motor 33 has a base 34 provided with a depending slide 35 mounted in an upwardly and outwardly inclined way 3S on the back of the housing i2. The surface of the way LA@ on which' about its. longitudinal axis, theY same includes.

a belt 4E) arranged to run over a relatively large pulley 42 loose on the long hub 43 of `a spur pinion. 44 which meshes witl'i a spur gear l5 keyed to a shaft '16 havinga worm Xl which meshes with a worm gear 48, the hub :i9 of which is mounted on the boring bar It. As shown, the pulleys l `and 4:2 have variable speed grooves into which the beit ii'niay he shifted tov drive,l

the boring bar I8 at different speeds, see Fig. 1;'

This belt [it maybe tensioned by manipulating the screw 39 heretofore lreferred to.

v The worm Gl' has a double threadthus doubling the speed at which the boring bar would be rotated by a single thread worm and the ratio 'of the pinion 34 and gear d5 is such as to reduce.'

the speed of the worm lll so that it turns the boring bar I 3 at the same speed at which it would be rotated by a single thread worm. The purpose of providing the worm il with a double thread is to reduce the frictionbetweensaid wormand the worm gear 8 and increase the power delivered to the worm gear d8 by the worm 47.

The hub 43 is journaled on a stub shaftv 59 rigidly secured to the housing i2 and the YshaftY l is journaled in a pair of axially aligned bear-r ings in said housing and the worm il is secured to the shaft 45 betweenV itsbearingasee Fig. 3.

A fixed collar 5IV on' the outer end of the shaftY 58 holds the pulley on the hub against out'. ward axial movement on said shaft. YThe hub 49 is mounted on the boring bar 8' between the two bearings 22 and is held thereby against axial movement. This hubfft, and henceV the worm gear 48, is heldfor 'rotation with the boring bar I8 but with freedom to permit said boring bar to move axially therethrough byva keyv 52 secured in said hub and slidably mounted in a loncr keyway 53 in the boring bar i8.YV Y

Referring now to the operating connections'for feeding the boring bar I8 axially during itsrotation the same includes aspur gear 5:'4` on the hub 49 which meshes with -a spur gear 55 fixed on the lower end of an upright shaft 555 having on its upper end a worm 5l which meshes with a worm gear 58 loose on the shaft 5S* having a xed spur pinion Sil which meshes with a rack SI on a fixed upright'post The shaft 56v extends parallel tothe axis. of Vthe boring bar .I8

and its lower end portion is-journaled in a pair of Vbearings 63 formed with the housing i2, one above and the other vbelow the gear 55. w f

A pair of collars '54 on the shaf 53 engage the outer-faces of the bearings 63 and. hold saidshaft bar,

y rod 24 for rotation therewith. Tins scale' E22 against axial movement. The upper end portion of the shaft 56 is journaled in a pair of axially spaced bearings 65 on a cross-head 5G with freedom to permit vertical movement of said head thereon. The wormV 5l is sescured to the shaft 56 for rotation therewith by a key 52' which works in a long keyway 68 in said shaft. The crosshead 66 is carried by the boring bar IS and has a long sleeve bearing S9 which slides on the post 62 during axialv feeding movement of said boring This cross-head 66 is provided with a hub 'I'having a bushing 'II in which the reduced upper' end `portion of the boring bar E3 is turnaoiy mounted. Formed on the upper end of the bushing 'II is an outturned annular flange 'l2 which has a working t between the hub 'Sil and the lower end ofthe boring bar extension 21 and holds said head against lifting movement on the boring bar. I8. A thrust bearing 'I3 is interposed between the lower end of the bushing 'il and an annular shoulder-,14 on the boring bar I8 and the boring -bar I 5 has free turning movement in saidbushing. ,Y

'5 Variable speed transmission mechanism from the wormrgear58 to the shaft 59 -includes differentialspur gears '1.5, I5 and 'I'Iiwhich mesh with spur gears '18, 'I9 and 80, respectively. The gears 58, 'I5 and 'I6 are all connected for common rotation and mounted for rotation on the shaft 55 and the gear l1 is keyed to said shaft. The gears I8 and 'IS-are loosely mounted on a shaft 8l for independent rotation and the gea-rti is` keyed-forrotation therewith'r and said shaft is mounted Yina bearing on the cross-head EG and extends Vparallel to'the shaft '59;v

A sliding key 82 mounted for endwise sliding movement in a long keyway 83 in the shaft BI is provided foreonnecting either one of the gears 'I8 and 79 to said shaft for rotating lthe same from the gear 5S. Thefkey 82` is provided with a knob 8A by which it may be shifted from neutral within-the gear 89 to a .position in which it pro-4 jects into any one of a plurality of` circumferentially spaced keyways 85 in thel gears 'IIB or "i9 to connect either one thereof to the shaft 59. ToY manually operate the pinion ISS)v to raise or lower the cross-head 66,. and hence the boring bar I8 and its cutter head I5, there is provided a handwheel 86 rigidly secured to a bearing il on the shaft59 and having a spur pinion 88 which Vmeshes with-a spur gear 89 keyed tothe shaftv 8 I.

The micrometer heretofore mentioned is for use` in positioning the operating rod 5M when manipulatedV to set the cutters. I9 for al predetermined cut. The skirt of the micrometer thimble 2 5 is telescoped with a working fit onto thevboring b'ar extension 21, which forms a part ofthe micrometer. This skirt of thethimble 25, aty its bottom, its inwardly. and downwardly beveled to a sharp edge,. which closely engages the exterior of the boringv bar yextension 21 and affords the body 90 ofa Vernier VSIL-which circumferentially divides the body 9i) into fifty equal parts, each part or graduation representingv one-thousandth of'an inch of the diameter of the cutter. `The micrometer further includesa'vertical sca-1e 92 on the boringbar extension 2T having equal graduationsvreadingfromtheV top down ande oh graduuation, represents fifty-one' thousandths. of an inch or one complete turnv of the micrometer' thimble 25 and also one complete turn ofthe pilotv 20 when said thimble is secured to the operating also includes a vertical reading line 93 for the vernici' 9 I-.` The scale 92, reading from. the top down, has every other lgraduation designatedv as follows:

Albi.

sumed that the 'diameter of the smallest'cut that can be-made by the commercial form of the cutter head i6 is two and iive-eighths inches. Taking this dimension as yan arbitrary working point the third graduation on the scale 92, designated bythe numeral 1, will indicate that the diameter of the cut that the cutters .I9 will make when the micrometer thimble 25 is adjusted with' its reading edge on the graduation designed by this numeral andthe zero point of the Vernier 9|V on the' reading line 93, is two and seven one-hundred thousandths of an inch. If the diameter of the out to be made is say, two and seven hundred one-ten thousandths of an inch, the thimble 25 will be turned on the boring bar extension 21 to bring the Vernier graduation I0 into registration with the reading line 93. For each complete rotation of the thimble 25, the same will be moved downward on the scale 92 one space, or in other words, one-fty thousandths lof an inch. According to the reading of the' micrometer in Fig. 1 the cutter blades I9 are set to cut the cylinder to a diameter of 3.100 inches.

As previously stated, the screw-threads 28"on the thimble stern 26 and the screw-threads 2| on the pilot 20 are of the same number per inch and the face of the conical member of the pilot 29 has a predetermined angle to the axis of the pilot 29 to project the cutter blades I9 a predetermined distance for each complete rotation of the operating rod 24.A In the present commercial form of themachine the screw-threads 2| and 28 are each twenty-two per inch and the angle of the face of the conical member of the pilot 263 is 29 to the axis of said pilot.

Obviously by turning the operating rod 24 to project the cutter blades I9 the micrometer thimble 25 will also turn therewith and cause said thimble to move axially on the boring bar |8.

This rotary and axial movement of the micrometer thimble 25 changes its reading on the scale 92 and the reading of the Vernier 9| on' the reading line 93 thus indicating at all times the diameter at which the cutter blades I9 are set to cut. It will thus be seen that thereading on the micrometer Will indicate the exact diameter at which the cutter blades are fset to cut.

yBy loosening the thumb-screw 30, the micrometer thimble 25 may be axially adjusted with respect to the boring bar 8 to correct its reading on the scale 92 and the reading of the Vernier 9| on the reading line 93.

In a broad sense the operating rod part or extension of the pilot 20. l

Before mounting the machine on av cylinder block and centering the same in respect to the cylinder to be rebored, the operator ascertains the part of the cylinder worn to the greatest diameter and then mounts the machine on said block with 2 4 iS a.

the cutter head above said block, its cutter bladesand thereafter the civierating4 rod 24 is turned by means of thehand-crank 32 to project the cutter blades'B and cause-,their cutting edgesl toimpingeag'ainst said wall.'V This engagement `ofV the "cutter blades |9'with the wall of the' cylinder causes the machine to shift bodily on the block and thereby automatically center the same. With the machine thus centered the saine is rigidly secured rto the block'by-a clamp 94. I

The reading vof themicrmeter is. notedv to ascertainthe diameter at ,whichthe cutter blades 2.9 Vare set'onr in other words, the greatest diameter 'of Vthe worn Cylinder; and thereafter the operating `rod 24 turned ina reverse direction to reiractthe cutter blades |9 to a diameter that will permit the'cutter-head |6 to be freely lifted from'thel cylinder." Next the hand-wheel 186 is again -operated to project the cutter blades |9 and the micrometer reset at the reading previously noted, thus setting the cutter blades i9 to the-same diameter at which they were set in -the cylinder. If it is desirable to cutthe cylinder to a still larger diameter the operating rod 24 may be further rotated to project the cutter blades I9 the desired number of thousandths lof an inch which is indicated on the micrometer.

.With the cutter blades |9 adjusted ior the demotor 33 and automatically operated to stop said `motor at Vthe completion oi.' each boring operatien through a cylinder. l

The automatic control for the switch 95 includes a vertically movable stem 91 mounted for endwise sliding movement in bearings 98 on the housing I 2 and has on its upper end a segmental head 99, which embraces said housing and holds the stem 91 from turning about its longitudinal axis. compressed between the upper bearing 98 and the head 99 and is under strain to hold the stem 91 raised. Rigidly secured to the stem 91 between the bearings 98 is a radially projecting trip finger |9| which overlies the switch member 96 for operating the same to close the circuit.

Cooperating with the head 99 is a collar |02 on the boring bar I8 and rigidly secured theretov 1 nger |0| to engage the movable vswitch member 96 and move the same downward into a position to close the circuit and stop the motor.

When the boring bar I8 is raised, the collar IDI will be lifted thereby from the head 99 allowing the spring |00 to reset the trip and the switch member 96 will remain in its lowermost position with the circuit closed until said memberv is manually operated to start the motor. To facilitate the turningof the micrometer thimble 25, the same is knurled, as indicated at |04.

A screw-eye |05, secured in the upper end of A the post 62, is provided, as one means, for hold- A coil spring |69 encircling the stem 91 isY ing the boring betrv I8 sus'p'endedfromaloist by which the boring machine may be swung kover an engine block in aniautomotivevhiole and then lowered onto the block Without dang'etofinarring or damaging the vehicle',

What I claim is: l Y l `f 1 In a portable boring machine, ajhollow base adapted to rest'upon an engine 4Cylinder block over a cylinder thereof;V a `housing on thebase, an upright tubular boring bait extending through Said hollowbase and"journaled in 'the housing foi' compound otaiy'fand' axial movements', a cross-head in 'whichfthe boring bajr at its upper end. is journalled; be'aiing'i'neans holding the cross-head for axial movement with the boring bar, an uprightgude pt dly' secured at its lower end to the housing', a radko'n the posh's'aid crosse-head' havin@ a hearing in Whih'the'st is slidably'nfmuntedy a'pinionjournaledon thecross; head and meshing with the'rack', an upright drive shaft journaled in" a bearing on the houing and he1d"fagainst 'axial movement' therein; a, Vbeating onk thev cross-head in which the drive shaft is ysaid pinion independently of 'the drive shaft to 1 THOR THORSEN. 

